Today I tried to write this on shell, I couldn't do it in a compact way. Are there some nice PLs for these kind of plays? Cleanest I could do was doing below in a single line via "python -c". I couldn't get it done via bc or awk.

  from random import random
  l = lambda (a, b), c: (a + c, b + 1)
  g = (1 if random()**2 + random()**2 <= 1 else 0 for i in range(10**6))
  r, t = reduce(l, g, (0.0, 0))
  print r / t * 4